. >>> and 49ers coach jim harbaugh steps up to the mic. but there's only one thing he wanted to talk about. >>> the promising news for weekend warriors and runners to fix those aching knees. >>> and the investigation into natalie wood's death take two. what a secret file reveals about the final moments of the star t starlet's life. >>> it's social media mystery that will be solved in less than 12 hours. facebook will address the hype and unveil something it's, quote, building. george kiriyama joins us from facebook headquarters in menlo park. do we know what it's building, george? >> reporter: jessica, we'll try to find out. will it be a new phone? a new search engine? there's a lot of speculation as to what facebook will announce tomorrow morning. tonight, we talk to facebook users to see what they want to see added or changed to the site. downtown palo alto is attracting customers with freshly-baked bread, dessert and coffee. but the store is trying to expand its customer base using facebook. >> a lot of people are on it. if we have a pr